1. Field of the Invention
The present invention relates to a system for operating poppet-type cylinder valves of a reciprocating internal combustion engine, so as to selectively control the duration of the valve opening events.
2. Disclosure Information
Variable valve duration control devices have been the subject of much invention during the past few decades. U.S. Pat. No. 5,373,818 discloses but one example of such inventive activity. The '818 patent describes a variable duration valve operating system having at least one embodiment which is useful with bucket tappets, but which is not useful for application to roller finger followers. A second embodiment may be employed with a finger follower, but in the context of an operating system having high inertia, and therefore, unacceptably slow system response time.
Other types of variable valve operating devices have been used, including such systems as axially shiftable camshafts, cam timing control devices, electromagnetically actuated valves, and yet other devices. The present system is readily usable with finger follower valve actuation systems and allows the control of valve events extending from no valve opening whatsoever (i.e., valve deactivation) to a maximum opening.